In the past few days I have come across a few articles that I think are interesting, from how the universe will end, to what is spacetime, even that scientists think that have proof that our universe is a hologram. All of these are very interesting.
First let’s start with what is spacetime? Honestly, I have no idea and the article really, in my opinion does not do a good job of explaining it. The easiest way for me to understand it or at least the easiest way the article broke it down was the following quote: “But no matter what the Universe is made of, the things it’s composed of need a stage to move on if they’re going to interact.” That makes the most sense, so spacetime is the stage that the physical world acts on. What is fascinating and something that scientist do not have a true answer for is that this stage, spacetime, is expanding at an increasing rate. Meaning things in the universe are getting farther and farther apart from one another faster and faster. Again scientist have no real reason for this, other than the Inflation Theory which I think includes Dark Energy, a substance that we have not seen or detected with any instrument. So it is tough to accept a theory that has a component that no one has ever seen, but we see the results and they are undeniable. Even though no one is even sure Dark Energy exists at all I think this is the most widely accepted theory to explain the expansion of the universe. While that is certainly interesting, what is also interesting is how something the universe will end.
There are any number if theories as to when or if the universe will end. There were a few that I had never heard of while other I was familiar with. Here are some of my favorites. The Heat Death Theory is one that I think will ultimately come to pass. This states that the universe will have cooled to almost 0 Kelvin and there will be almost no molecular movement anywhere in the universe. BUT what is fascinating about this is that no matter how much time passes that no system (the universe) will ever be 0. It will be very close but never 0. I think this will probably happen when our universe comes to an end.
Some other cool ones are the Big Crunch and the Big Rip. These are basically opposites. The Big Crunch says that because the universe is accelerating away soon it will reach a limit and then start to contract, in which it will condense back in on itself, like a rubber band. When you stretch a rubber band too far and let it go it snaps back, that is what this theory is saying, but replace all matter in the known universe with the rubber band. With the Big Rip, this says that this universe will continue to expand infinitely and eventually just be ripped apart. The expansion will pull galaxies, planets, molecules, then atoms apart to a point where everything will be ripped apart. Pretty crazy.
There is also a theory that says that time will just end. I did not quite understand that one? But one of my favorites is the idea of a cyclical universe. I like this idea because even though one universe may come to an end, there is another created, so it never truly ends just gets recycled so to speak. This is where it is fun to speculate and even though none of the scientist in the article say it, I think a combination of a few of these theories may be the real truth.
Of the Big Rip and the Big Crunch I think the Big Rip is more likely to take place along with the Heat Death of the universe. Those two seem to go well together as they both complement each other. Pulling everything in the universe apart will certainly lead to matter being spread out and eventually to the Heat Death of the universe. While that is all well and good I think there are some more fascinating scenarios when you start combining theories like the Cyclical universe. So if this theory is true that means that the universe is something that cannot fully be destroyed. Once this one comes to an end, through some bizarre circumstance a new one is created. That bizarre circumstance is what I think is interesting.
So let’s say that the Big Crunch is true and will happen. So all the matter in the universe will eventually coalesce and come together in a single point. This single point would be infinitely dense and all the known laws of physics would break down, this is called a singularity. If this were to happen and it did create a singularity it could be the birth of a new universe, much like the Big Bang created our current universe. This could happen infinitely so on and so forth. The problem is that I am not sure what would make the universe stop expanding and suddenly begin to fall back in on itself. That is a problem with the theory. But again scientist think this still may be possible.
As I said I think the more likely one of the two to happen is the Big Rip, so how would this theory combine with another to create a cyclical universe? That is a really good question that I do not have an answer too. I read that my following theory could potentially violate the conservation of energy, but it could also be possible. So let’s just say there is a chance. Let’s say that the Big Rip happens and everything from planets to atoms are being ripped apart. I do not know if it is possible that the Big Rip could trigger a chain reaction explosion from atoms being ripped apart. This probably would not cause a singularity but could introduce more energy back into the system, but I am not sure how that would help and if that would even make a difference.
With all that being said I am not sure how the big rip could lead to another universe? From everything I have read about the universe, it will eventually come to an end, the question is how? I firmly believe that no living organism will be alive at that time to witness what is going on so on some level it really does not matter. But as always the speculation is fun.